Lamp socket



M y 5. 9 J. F. CAVANAGH 8 LAMP SOCKET Filed Feb. 21, 1941 HVVENTOR.

ATTORNEYS Patented May 5, 1942 LAMP SOCKET John F. Cavanagh, Providence, R. I., assignor to Guy H. Burt, Providence, It. I.

Application February 21, 1941, Serial No. 380,017

3 Claims.

This invention relates to electric lamp sockets, and more particularly to that type of socket used for double-ended discharge type lamps in which a filamentary electrode is mounted at each end of the lamp.

In conventional sockets used for this type of lamp, the base of the lamp so covers the socket and the contacts that it is difiicult for the user to know exactly the manner in which a lamp which is placed in a socket is to be removed therefrom. Consequently, in attempting different kinds of movements for the removal of the lamp from the socket, breakage frequently occurs. Also, breakage sometimes occurs in the insertion of the lamp into the socket due to misalignment of the contact pins with respect to the contact elements of the socket and the attempted manipulation of the lamp when the contact pins are out of their particular alignment, which is necessary to bring them into engagement with the contacts in the socket. Furthermore, sockets which have heretofore appeared on the market are usually made in two pieces requiring additional assembly operations and, in many instances, they are of a design which enables them to easily become clogged with dirt or foreign matter.

One of the objects of this invention therefore is to provide a socket which is of such a character that breakage of lamps due to insertion and removal will be minimized.

Another object of the invention is to provide that type of socket in which the lamp is inserted and then twisted about an axis within itself into its final seated position.

Another object of the invention is to use one of the contact pins as a positive pivot for the rotation of the lamp about an axis within itself into its final seated position.

Another object of the invention is to provide a moldable socket which is so shaped that it may be formed all of a single piece of material.

Another object of the invention is the elimination of rotating or relatively moving parts in the socket.

Another object of the invention is to reduce to a minimum grooves and slots which may collect dirt and hamper the use of the socket.

With these and other objects in view, the in vention consists of certain novel features of construction, as will be more fully described, and particularly pointed out in the appended claims.

In the accompanying drawing:

Fig. 1 is an elevation of the socket illustrating in broken lines the position of a lamp in the socket;

Fig. 2 is a rear view of the structure shown in Fig. 1,. showing in dotted lines the contact pins of the socket in place;

Fig. 3 is a section on substantially line 3--3 of Fig. 2;

Fig. 4 is a perspective view of the lower portion of the socket;

Fig. 5 is a perspective view of the same portion of the socket as shown in Fig. 4, but looking at the other side thereof;

Fig. 6 is a perspective view of one of the contact arms;

Fig. 7 is a perspective view of the other of the contact arms.

According to the present invention the socket which I have provided is molded of a single piece of electrical insulating material so shaped that it may have assembled therewith two contact arms for engagement with the usual end contact pins of the fluorescent lamp to be received in the socket, and having binding screws for connection of electric lead lines to the socket by which the lamp is arranged to be supplied from a source of electric current.

The body portion ll! of the socket has a smooth face I I and a back portion provided with grooves as at l2 and I3. The head portion of the socket, I4. is made thicker than the body portion and it is grooved as indicated at l5 and I6. As illustrated in Figs. 1 and 4, the lower portion of the body It] is shown as being provided with an island H which is separated from the main part of the body by an arcuate groove IS.

The island I1 is shown as being slotted as at l9 for the reception of one of the contact pins 20 of the lamp. A contact arm 2| located in the groove I3 is provided at one end with an arm portion 22 that extends within and across the groove l9, and this arm portion is recessed as at 23 so as to frictionally engage the inner side of the pin 20 and to form a stop for the insertion of the pin 20 and frictionally locking the same in the socket. Thearm 22 is resilient and thus is free to be flexed away from the pin 20 when the lamp is manipulated to be removed or to be inserted.

The outer-surface of the island I1 is designated generally 24 and this surface provides a guide for the second contact pin 25 of the lamp so that when the first contact pin 20 has moved into the slot [9 to engage the stop 23, the first contact pin will act as a pivot about which the other contact pin 25 will be swung while being guided during its swinging movement by the arcuate surface 24 of the island ll so that the second contact pin 25 will be moved into electrical connection with the other contact arm 26 of the socket.

responding recess'28 in the outer surface of the island l1, and formed in this tongue memberis a notch 29 to receive the second contact pin 25 of the lamp. The distance between the recessed contacting portions 23 and'29 is preferably made such that normally the portion 23 will be a greater distance from the contacting surface of the portion 29 than the space between the respective contact pins, thus causing some flecture of the portion 22 for such engagement and causing the part 23 todraw=down the contact pin so 1 that the contact pin 25 is pulled firmly into en- A resilient tongue member 21 projecting from one end of the arm 26 is setinto a corgagement with its corresponding contact notch 29 in contact arm 2|.

The contact arm 2| is provided at its other end-with a plate portion 30 having a threaded from. It will be observed from the foregoing description that the present invention provides a socket which is very efiicient to manufacture, one whichwill not collect dirt, and one which provides a positive pivot point for swinging movement of the lamp into and out of its working position.

I claim:

1. In a socket for engagement with a lamp element provided with a pair of contact pins, a base member of electrical insulating material provided with a face, a pair of contacts in said base member, a slot in said face extending thereunto from one edge thereof and having straight line side walls leading to one of said contacts for guiding one of said lamp contact pins into engagement with one of said contacts, and a second slot insaid face extending generally laterally of the first slot and having a curved guide surface through which the other lamp contact threaded opening 34 which receives the binding screw 35. The socket is recessed as at 36 (see Fig. 5) so as to receive a back cover element 31 which is placed over the back of the socket. The cover 31 is formed of some electrical insulating material and when in place serves to retain the contact arms Hand 26 in their respective positions.

By this arrangement, it is merely necessary to insert the contact pin 20 of the lamp into the groove I9 and with this pin as a pivot then turn the lamp either in a clockwise or. in a counterclockwise direction to swing the contact pin 25 about and along the curved guide surface of the island l1 and be guided by such surface into electrical engagement with the contact 21 and received by and firmly held in place by the notch 29. For convenience and symmetry the island I1 is shown in the illustrated embodiment as being of circular shape, although it need not necessarily be limited to that particular shape as long as a curved guide surface is provided close to the contact portion 21 whereby this guide surface will act to direct one of the contact pins of the lamp into engagement with the contact 21 and into the notch 29 for firmly holding it in position, after being swung about the other contact pin as a pivot. It will be seen from the construction as above described that the socket has no moving parts and may be made all in one piece, except the back cover 31.

The island has its guide surface 24 so arranged that the outside of this surface does the guiding of the-contact pin 25 and no arcuate form of slot I 8 is necessary. The slot I 8 there fore may be made sufliciently large so that really no slotted formation need be present. The only slot which is necessary is the slot l9 which open downwardly so that any dirt tending to lodge therein would be immediately discharged therepin may move into engagement with the other contact upon rotation of said lamp element with the first lamp contact pin as a pivot.

2. In a socket for engagement with a lamp element provided with a pair of contact pins, a base member of electrical insulating material pro vided with a face, a pair of contacts in said base member, a slot in said face extending substantially longitudinally of the base from one edge thereof and having straight line side walls leading to one of said contacts for guiding one of said lamp contact pins into engagement with one of said contacts, and a second slot in said face having guide walls to direct movement generally laterally of the first slot and extending across the member to open at either side edge of the member through which the other lamp contact pin may move into engagement with the other contact upon rotation of said lamp element in either direction with the first lamp contact pin as a pivot.

3. In a socket for engagement witha lamp element provided with a pairof contact pins, a

' base member of electrical-insulating material provided with a face, a pair of contacts in said base member, at least one of said contacts being flexible and resiliently urged in a direction away from the other contact when flexed toward it, said contacts'being so located as to normally have their engaging surfaces positioned apart a distance greater than the distance between the pins of the lamp element to be engaged, and slots in said face extending longitudinally and laterally of the base and leading to said contacts for guiding one of the lamp element pins'to one contact and then by swinging movement guide the other lamp element pin to the other contact to cause the pins to straddle said contacts and by insertion to relatively move said contacts toward each other whereby the tendency of said contacts to move apart applies pressure on the pins of the lamp element from a point between th pins outwardly.

JOHN F. CAVANAGH. 

